Carl Goldberg Chipmunk 400
The Carl Goldberg Chipmunk 400 is a low-wing, electric ARF exhibition/air show airplane marketed as an intermediate low-wing aerobatic park flyer-class aircraft. It is approximately the same size as most foam aircraft, but is jig-built of laser-cut balsa and polyester film construction. "Street" price is comparable as well, making the Chipmunk 400 a viable alternative to foam aircraft. The Chipmunk's standard stick mount will accept gearboxes and "inrunner" brushless motors from most manufacturers. If an "outrunner" or direct drive motor is preferred, an E-flite stick to direct drive adapter may be fitted. A considerably larger glow-powered version requiring a .45 to .60 two-cycle or .60 to .90 four-cycle engine is also made by Carl Goldberg. About the prototype The original aircraft, serial 116-154, is a de Havilland DHC-1B-2 Chipmunk trainer built at the de Havilland Toronto plant as part of an order by the Canadian Department of National Defense and originally test flown on August 29, 1950. Intended as a means to train civilian pilots for reserve work, the plane represented by the model was registered as CF-CXL to the Winnipeg Flying Club and delivered to them in October 1950. It was placed on inactive reserve in late 1957 and remained in storage until June 1961 when it was offered for sale. In January 1967, after changing hands twice, the plane was purchased by Sabre Industries of Winnipeg for Robert "Skip" Volk, owner of the Aqua Craft Boat Company of La Verne, California, USA. Volk was a friend of well-known aerobatic pilot Art Scholl. Scholl introduced Volk to flying, coached him in aerobatics and set him on the path to a career in exhibition flying with the possibility of sponsorship by Pennzoil. Modification for exhibition flight began soon afterwards and the aircraft received its final FAA registration number, N1114V. The model's livery is that of its 1978 marking scheme and would remain so until 1985, when Scholl was killed while piloting a Pitts during the filming of the movie, Top Gun. Scholl's widow Judy donated his aircraft to museums, with N1114V going to the EAA AirVenture Museum in Oshkosh, Wisconsin. Pilot Kevin Killingworth and Kevin Kammer, Art’s chief mechanic, delivered the plane on June 12, 1987 with 5183.5 total hours on the airframe. Construction recommendations The ARF design is straightforward and is easily assembled. It is recommended to line the cowl with 1/4-ounce fiberglass cloth and either epoxy or resin in order to reinforce it. Both the cowl and prototypically correct wheel pants are quite brittle; it may be desired to leave the pants off since the replacement cost is extremely high at US$20 plus shipping. Hardware quality is generally good, but the landing gear struts supplied with the kit are very soft and will bend on most landings, especially on grass. New struts can be bent with .047" piano wire. This gauge is marginally larger but will still fit in the wing saddles and will still accept the supplied wheels and tires. It is also recommended to forego the supplied control horns and to substitute DU-BRO micro control horns. The factory parts may break at the mounting pins in flight. The covering on most ARF kits often require touchup with an iron or heat gun and the Chipmunk is no exception. Instructions for touching up the covering are discussed in the assembly manual. Flight characteristics As is typical of a low-wing sport aircraft, the Chipmunk 400 is best flown at relatively high speeds. Too low an airspeed causes the model to become unstable, especially during landings. Some power is needed on landing, which means the model will tend to want to remain in flight. Discussion boards recommend the use of a radio that will mix "flaperons" to both reduce airspeed and maintain control. High airspeed makes the model want to climb, requiring quite a bit of down elevator. Trim is somewhat difficult to achieve, but the result is a very aggressive park flyer limited only by the pilot's skill. The model's control surfaces are hinged with CA hinges which are recommended over pinned hinges. Use of pinned hinges leaves a gap between the leading edge of the aileron and an uneven trailing edge between aileron and wing. The extra leverage makes for touchy aileron control. Specifications *'Wingspan': 38"/97 cm *'Wing area': 230 sq in/1484 sq cm *'Length': 28.5"/72.4 cm *'Flying weight': 22 ounces/624 grams with required 3S 1500mAh lithium polymer battery *'Propulsion': Brushless outrunner motor, 25-amp brushless speed control (not included) *'Radio requirement': Four-channel with four sub-microservos and micro-receiver *'Catalog number': 12023 External links and references *Chipmunk 400 home page Category:Aircraft *Order form for online instruction manual *EAA AirVenture Museum page for N1114V